Dynamo-electric machine.



E. J. ANDREWS. DYNAMO ELECTRIC MACHINE.

APPLKCATION FILED DEC. 18, 1912.

Patented May 23, 1916.

3 SHEETSSHEET 1- FIOB.

E. L ANDREWS,

DYNAMO ELECTRIC MACHINE.

APPLICATION HLED DEC-18,1912: 1,184,157.

3 SHEETSSHEET 2.

Patented May 23, 1916 E. J. ANDREWS.

DYNAMO ELECTRICMACHINE.

APPLICATION FILED 05c. I8, 1912.

1,1 84,1 57 Patented May 23, 1916.

V 3 SHEETS-SHEET a.

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UNITED STATES PATENT OFFICE.

ERNEST J. ANDREWS, OF CHICAGO, ILLINOIS, ASSIGNOR- OF ONE-IOURTH TO GEORGE L. CHINDAHL, OF CHICAGO, ILLINOIS.

DYNAMO-ELECTRIC MACHINE.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed December 18, 11-112. Serial No. 737,411.

To all whom it may concern Be it known that I, Enxns'r J. ANDREWS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

This invention relates to dynamo-electric machines adapted to be used both as variable speed motors and as variable voltage or variable speed generators. For example, such machines as are to be used with internal combustion engines to start or boost the engine, and to generate electric current for ignition, lighting, warning signals, foot warming. and other purposes.

It has been found in the use of dynamo electric machines in connection with internal combustion engines that, as commonly constructed, the machine either must be very large in order to have sutlicient power to start the engine, or must be run when generating at a very high speed. If the machine is very large the weight and space required as well as expense render its use undesirable. This is particularly so in view of the fact that the large size is a disadvantage when generating, as less than full loads will be required, and the efliciency will therefore be low. If the size of the machine is reduced by increasing the speed, the high speed will cause undesirable noise and serious wearing of the moving parts. As ordinarily constructed the speed of the machin when generating is materially greater than the speed when starting or boosting,

and as the machine is generating most of the time, the disadvantage of the high speed is much greater than it would be if the ma chine ran at high speed when starting.

Hence, one of the objects of this invention is to produce a dynamo-electric machine so constructed that it may run at high speed as a motor when starting th engine, bu at a much lower speed when generating. Running at the high speed as a motor gives sufficient power for starting. and as the time required to start is so slight the power is thus obtained without any material disadvantage. At the same time my invention provides for a machine that by running at low speed will generate sutliciently high voltages, and thus the undesirable noise and wearing of the parts because of high speed as a generator is largely eliminated, and the generator, being small, will. be run at substantially full load, and hence at high elliciency.

It is very desirablein the use of any apparatus in connection with internal combustion engines, particularly when used on antomobiles and trucks, to be able to operate the apparatus quickly and simply. For various reasons, the operation should involve as little work and should take as little time as possible on the part of the operator. It has been found that the use of dynamo electric machines for starting, boosting. and generating purposes involves ordinarily the operation of so many levers and switches that confusion is likely to result, particularly at times when quick operation is necessary.

Hence a further object of this invention is to provide a dynamo electric machine for the purposes specified, the operation of which is extremely simple, requiring but one operating switch for all purposes, and the entire electric operation at any time consisting in merely throwing the switch on or off in the ordinary manner.

In carrying out the former object I have taken advantage of certain principles which are well known to those skilled in the art of dynamo-electric applications.

lVhen a dynamo-electric machine is operated as a motor, the speed and power of the motor will be substantially proportional to the number of circuits in the armature. If the number of circuits is increased without varying the number of inductive conductors in use, both the speed and the power willbeincreasedatthesamerate. Atthesame time the electromotive force of the machine as a generator. increases substantially inversely in proportion to the number of ci cuits. Now, with a dynamo electric machine in use, with an internal combustion engine. bv having a large number of circuits through the armature when the machine acts as a motor, the power capacitv is correspondingly large. and a correspondingly small machine is thus able to start the engine. Then by reducing materially the number of circuits when the machine acts as a generator without varying the number of inductive conductors the electromotive-force is varied in ersely and is therefore increased in proporti n to the eduction in the number of circuits; a d the machine is thus able to generate sufiicient electromotive-force to suitably charge the battery when running at a much lower speed than when running at full load as a motor. It should be understood that the electrometive-force generated is also proportional to the speed of the machine, and that the generating voltage must be higher than the motor-operating voltage. Ihe latter is so because the voltage drop through the machine brushes and the wires must be carried by the battery when the machine acts as a motor, but must be carried by the machine when it acts as a generator. This voltage drop frequently amounts to two volts; and, if so, the voltage of the generator must be substantially four volts more than the effective voltage received by the motor from the battery. And with low voltage machines, such as are required for the purposes specified, this voltage drop becomes a very material proportion of the entire voltage. Ordinarily, this voltage increase of the generator is produced by increasing the speed of the generator. By the use of my invention I am able to increase the electromotiveforce generated by decreasing th number of circuits through the armature and thus increasing the number of inductive conductos in series, and also to materially reduce the speed of the machine as a generator relative to its speed as a motor.

An ordinary drum armature may have the number of circuits therethrough varied by changing the connections of the coil leads without disturbing the coils themselves. If the armature is wave-wound, by properly shifting the connections of the armature coil leads, the armature may be changed to a lap winding, and in such a case the number of circuits through the armature will be doubled. And one of the steps of the process by which I carry out my invention is to change the wave windings of the armature of a four-pole electric machine to lap winding by properly varying the connections of the coil leads. Also with an ordinary lap wound armature, by properly shifting the connections of the coil leads, the armature may be changed from what is called a simplex to a duplex winding, and the number of circuits of the duplex winding is twice that of the simplex winding. Or, if the winding is changed from a simplex wave winding to a duplex lap winding, with a four pole machine, the number of circuits will become four times as great. And the general process by which I carryout my invention is to change the windings of the armature of the machine used from a simplex wave winding to a duplex lap winding without varying the number of inductive conductors in use. And, as will be seen hereinafter, such a change may be made in a very simple manner.

It will now be evident that if the machine a motor may be suflicient to start the engine,

and the electromotive-force of the machine as a generator may be suflicient to properlycharge the battery even though the speed as a generator is much less than the speed as a motor when running normally.

In my application for patent filed June 11, 1912, Serial No. 702,955, I have described one method of applying a dynamoelectric machine to an internal combustion engine; and the application of the machine herein described may be made as described in said application, or in any other suitable manner. In the same application I have described a method by which suitable changes may be made in the windings of the machine in order to vary the number of circuits. hen the machine starts the engine the engine shaft resists the rotation of the armature shaft, and the rotation of the armature relative to the engine shaft causes a switch to change, in a suitable manner, the windings of the armature so as to increase the number of the circuits, the machine normally having the windings in condition for generating. The machine herein described is adapted to be operated in a somewhat similar manner. hen the armature starts to drive the engine a suitable switch automatically changes the COHHQL- tions of the armature coils so that the armature passes from a simplex wave to a duplex lap winding, provided the machine was last used as a generator. And when the en gine starts to drive the armature shaft to generate current, the relative rotation of the two shafts causes a switch to so change the coil connections that the armature passes from a duplex lap to a simplex wave winding, provided the machine when last used was used as a motor.

The switch used herein for varying the number of circuits through the armature, and the specific method of operating the switch, however, are materially different from said prior application and will be fully described herein, as well as the manner of application of the switch to the coil ter minals and the changes which are made in the windings of the armature by means of said switch.

In the accompanying drawings, Figure .1.

is a diagrammatic view of an electric svstemconnected with an engine, which illustrates my invention. Fig. 2 is a diagrammatic view of an armature and acircuit changer embodying features of my invention, the proper pitch of the coils, however, being ignored in order to avoid confusion by the overlapping of the coils. ordinary pitch for four-pole machines In practice the would be used. Fig. is a diagrammatic view of the windings and the connections thereof to the commutator and the circuit changer, showing the pitch of the coils as I have selected it in this instance for the exempliiication of that portion of my invention. Fig. is a central. longitudinal section of the armature. Fig. a is a section on the line 1 of Fig. 3. Fig. 5 is a section on the line of Fig. 3. Fig. 6 is a section on the line 6 of Fig. Fig. 7 is a detail view of one of the elements of the means for operating the circuit changer. Fig. 8 is a fragment-a1 plan view of the circuit changer with certain parts omitted.

In the drawings, the engine A is shown connected to the dynamo-electric machine B through the magnetic clutch C and reducing gear D. The battery E is shown operatively connected with the electric machine and the spark coil F and distributer G. hile mounted upon the dash or switch board II is shown the operating switch I, an ammeter J, and an operating lever K. The purpose of the lever K will be fully explained hereinafter.

The armature (Fig. 3) of the machine 13 comprises the shaft 1, the core 2, the coils 1, which may be mounted in slots in the core in the ordinary manner, a commutator 4t, and a circuit changer 5, the circuit changer in tiis instance, being mounted on the rear end of the shaft 1 of the armature. For reasons that will be apparent hereinaiter, the core of the armature is mounted nonrotatably upon a sleeve (3 which rotatably encircles the shaft. Collars 7 and 8 pre rentlongitudinal movement of the circuit cianger and armature core with reference to the shaft. and a key 9, as will be expained hereinafter, limits the amount of rotation of the sleeve with reference to the shaft, while a key 10 prevents movement of the core with reference to the sleeve. Tae terminals 11 of the coils of the armature are connected to the circuit changer in this instance, instead of to the commutator, and the commutator segments 12 are connected, by means of conductors 13, to the coils, as shown more clearly in Fig. 2.

In Fig. 2 the coils of the armature are indicated by the numerals 1st to 20. In practice the pitch of these coils would be similar to the ordinary pitch of coils for four-pole drum-wound armatures and sul stantially equivalent to 90. As such an arrangement in the diagram would confuse the drawing. the coils are shown without reference to the pitch in order to avoid overlapping. The commutator segments 12 are shown outside of the coils. and the poles 21 are shown outside of the commutator segments. The circuit:- changer 5 may be of any suitable form. In this instance it comprises the contact pieces 23, 2e and 25, shown inside of the coils; and the electric connectors 22 connecting certain of said contact pieces to other contact pieces, as shown. The contact pieces are positioned adjacent the coils of the armature and are immovable with relation to the armature core; the contact pieces 2i are positioned a substantial distance away from the conact pieces but are fixed with relation to said contact pieces 23 and the armature and the contact pieces 25 are positioned between the other two sets of contacts and are non-rotatably, but slidably, fixed with ref erence to the other contact pieces and the armature.

In F the coils of the armature are so indicated as to show the pitch of the crils, the field poles being indicated by the dotted lines 21, the periphery of the armature being indicated by the lines 21 and the slots of the armature being indicated by the lines 21 as shown, each slot inclosing four turns of the coils.

The contacts may be fried in any suitable manner to a ring of insulation 26, and may be formed in any suitable manner. In this instance I have formed them out of strips of conducting metal bent into the form shown in Fig. 8, and they are held in place by being forced into slots 27 cut in the insulation ring the loops 28 preventing the contacts from moving out from the slots longitudinall and a retaining band 29 6) on the periphery of the ring, preventing radial movement of the contacts. Contacts may similarly mounted in the insulation ring 30. Contacts 25 may be mounted in slots 31 in an insulation ring 32, and may be held in place by means of the insulation clamps secured b means of ncidh 3i. to the ring on. each side of the contact pieces I Ring 23 is lined to a disl: 3 1, the contacts being insulated from the diet: 3i 7 means of an insulation ring; The disk 3% fixed to the sleeve 6 in any su tabl manner. The ring; is fixed to a di the co acts fi l; being insulated fro n the dish by means of the ulation r ng- And the dislr S6 is fixed to the li lt means of bolts and sleeves 32 is non-rotate. the sleeves w 3 1- and 3G, ant.

by means of reference to the disks rigidly fixed to a ring pins 4. or in any suitable manner. th sale 41 on the shaft being threaded into id It will be seen tha v eat. if the armature leeve 6 are rotated snaft the. ring 40 will rota e. with said core: and if theshaft 1 does not rota e. ring 4-0 will be moved longitudinallv on said sha t by means of the thread Evidentl if the motor should be used to start an internal combustion engine relative rotation of the sleeve and the shaft would occur, as much greater torque would be required to rotate the shaft than merely to rotate the sleeve on the shaft. Hence, in such a case, the ring 40, carrying with it the movable contacts 25, would be moved longitudinally on the shaft and the contacts would be forced between the contacts 23 or 24, depending upon the direction of rotation of the armature. If the direction of rotation of the armature in such a case is clockwise, viewing Fig. 3 from the commutator end, it is evident that the ring 40 will be moved toward the disk 34, and this will carry with it the contacts 25, forcing them between the contacts \Vhen the contacts 25 have been forced home between the contacts 23, it will be seen, by a consideration of Fig. 2, that the coils of the armature will be connected as duplex lap windings. Considering the coil 15, and following the winding in a clockwise direction. it will be seen that the final terminal of coil 15 will be connected to the initial terminal of coil 17, and so on with alternate coils around the armature; while the final terminal of coil 16 will be connected to the initial terminal of coil 18, and so on with alternate coils around the armature. So that there will be two independent lap windings in the armature, and the machine will be adapted to act as a high speed motor.

The engine shaft, it should be understood, is connected through suitable mechanism to the shaft 1. If the engine shaft drives shaft 1, and thus tends to drive the armature and generate a current therein, the resistance of the armature to rotation will overcome the friction between the sleeve and the shaft, and the shaft will rotate with reference to the sleeve. In such case, if the rotation is in the same direction as before, ring 40 will be moved outwardly from the core and contacts 25 will be driven home between contacts 24. And in this case a consideration of the connections indicated in Fig. 2 will show a simplex lap winding of the coils. The final terminal of coil 15 will be connected, by means of one of the connecting conductors 22, to the initial terminal of coil 19, while the final terminal of coil 19 will be connected to the initial terminal of coil 16, and so on with a regular simplex wave winding alternating around the armature, one coil 20. being disconnected and dead, as is usually the case with wave windings, and the machine is then adapted to act as a comparatively high voltage generator.

Evidently it is necessary to provide means to prevent the relative rotation of the armature and of the shaft when the contacts are pushed home. Any suitable means may be provided for this purpose, but herein I have provided collars 42 and 43. hen the ring 40 comes in contact with either ring 42 or 43, the movable contacts will be in proper position, and relative rotation between these rings will be prevented; so that if the rings 42 and 43 are fixed rigidly to the shaft, relative rotation will cease at the proper time. But as this arrangement is likely to produce binding between the two rings which come in contact, and thus prevent relative rotation when it is desired to shift the ring 40 again, I have provided fur ther means to prevent such binding. These means comprise pawls 44 and 45 so arranged as to come in contact with the projections 44 and 45 of the keys 9, in the shaft, at

the proper time to prevent further relative rotation. hen the pawls are used, the collars 42 and 43 are fixed to the disks 36 and 34 respectively, and are free to rotate on the shaft when the pawls are in the elevated position indicated in Fig. 6. When in this position, pins 46 project into aper-' ture 47 in the flange 48 of the collar 42 and prevent coaction of the pawls 44 with the projections 44 of the key in the shaft. When ring 40 approaches collar 42, pins 49, projecting from the ring, come in contact with the pins 46 and push the pins against the springs 50 until the pawls 44 are free, under the action of the springs 51, to move into coaction with the projections 44, and prevent further rotation of the collar 42 and hence of the armature with reference to the shaft. hen the ring 40 is moved toward the collar 43, pins 52 act similarly upon pins 46 in the pawls of collar 43. At the same time, as the collar 42 will be rotated relatively backwardly, the pawls 44 are pushed outwardly by the projections 44 until the pins 46, under the action of the springs 50, again lock the pawls in their inoperative positions. By these means the armature core, and hence the ring 40, will always be free to rotate in such a direction as to move the ring away from the collar 42 or 43 with which it may be in contact. But the armature will no longer be free to rotate when the pins 49 or have moved suificiently to push the pins 46 inwardly and release the pawls 44 or 45 so as to allow them to coact with the projections of the keys of the shaft.

The terminals of the coils of the armature may be connected to the respective contacts of the circuit-changer in any suitable manner. Herein I have shown the leads 11 from the coils passing outwardly from the armature core in the usual manner. Of these leads, those which, as indicated in Fig. 2, are connected to the contacts 23, pass directly to the contacts, and may be soldered thereto in the usual manner. The leads 11 which pass to the contacts 24, extend over an insulation cylinder 55, which surrounds the circuit-changer, to the contacts 2- and may be soldered thereto in the usual manner. The loads 11 which are con nected to the movable contacts 25, pass over the ring 26 and downwardly into connection with the contacts in a y suitable manner, these leads being left suiiiciently slack to allow the rings to move freely from one position Contact to the other.

In practice the operation of the electric machine is as follows: When it is desired to cart the engine, the operating switch I is thrown in in the ordinary manner, causing the armature of the machine to rotate. The rotation of the armature may be considered, in this instance, as being cloclnvise when viewing the commutator end of the armature. The shaft of the armature will be held from rotation by means of the engine, and the relative rotation the armature on the shaft will move ring it) tovrarc c illar ill. The pins 52 will force the pins 46 from the locked position soon as contacts 2 are pro ierly in contact with the contacts The paw-"ls will then be forced into coaction with the projections 415 of the keys of the shaft by means of the springs 51, and relative rotation of the an ature and shaft will cease. This will cause the engine shaft to rotate and when suiiicient speed of the engine has been reached, explosions will occur and the engine will run normally under its own power. The operating switch may then be opened and the electric machine will, by the same action, be disconnected from the shaft of the engine, by the deenergizing of the magnetic clutch C.

If it is desired to generate current for the battery or for other purposes, the switch may be l ft in its operative position, or n ay be thrown therein when desired. This will cause the engine, by means of the clutch C, to drive the armature of the electric machine, and, as current is generated, the torque of the armature will overcome the frictional resistance between the shaft and the sleeve 6, and wi l cause the shaft to rotate ahead of the armature and thus shift ring l-O toward the collar 42. The pins i9 at the proper time will cause the pawls it to coact with he shaft key projections, the relative rotation will cease, and the machine will generate current normally, with contacts 25 between contacts The dynamo-electric machine may be used, as suggested, in connection with a nonstarting engine, in order to start or boost the engine, and to generate electricity when the engine is running under its own power. In such a case, any suitable reduction gearing may be used be ween the machine and the engine.

It is to be understood that I have her in described with some particularity various mechanical and electrical features in order to more clearly illustrate my invention but .1 7

that various modifications may be made by those skilled in the art without departing from the scope of the following claims.

I claim as my invention:

1. A dynamo electric machine comprising an armature, a circuit changer connected to the coils of said armature, and a shifting contact piece included in said changer, when said contact piece is in one position, said coils being wave-wound, when said con tact piece is in another position said coils being lap-wound.

2. In a dynamo electric machine, an armature and a circuit changer having a plu rality of contact pieces, ach of the terminals of th coils of said armature being connected to one of the contact pieces of said changer, a commutator on said armature, each of the segments of said commutator being connected to one of the contact pieces of said changer. and means for operating said changer, whereby the number of circuits through said armature is varied.

5. In a, dynamo-electric machine, an armat a plurality of coils and a circuitchanger mounted on said armature, said circuit-changer having a plurality of contact pieces, the respective terminals of each of said coils being arranged to be alternately connected y said circuit-changer to terminals of coils on the opposite sides of said armature and to terminals of coils 0n the same side of said armature.

-I-. In a. dynamo-electric machine, an armature, a plurality of coils, and a circuitchang r mounted on said armature, said changer having a plurality of contact pieces, the terminals of each coil of said armature being connected to contact pieces of said changer, the contact pieces of said changer being caress-connected with contact pieces on the opposite side of s id changer, said changer comprising means for rendering said cross-connections inoperative.

In a dynamo electric machine, an armature, a plurality of coils on said armature, and a circuit changer comprising a plurality of fixed contact pieces, each of the terminals of said coils being connected to one of said contact pieces, and means for alternately connecting said contact pieces to connect said coils into wave windings and into lap windings.

(S. In a dynamo electric machine, an armature, a plurality of coils mounted on said armature, and a circuit changer comprising a plurality of inner fixed contact pieces and a plurality of outer fixed contact pieces, and a plurality of movable contact pieces, one of the terminals of each of said coils connected to one of said inner pieces, and the other terminal of each of said coils connected to one of the movable pieces, each of the fixed inner pieces being connected to a fixed outer piece on the opposite side of said changer, and means for shifting said movable pieces from contact with said outer pieces into contact with said inner pieces.

7. In a dynamo electric machine, an armature, a plurality of coils mounted on said armature, and a circuit changer having a plurality of inner fixed contact pieces, a plurality of outer fixed contact pieces, and a plurality of movable contact pieces, the homologous terminals of each coil connect ed respectively to an inner piece and a movable contact piece, and each of the inner pieces being connected with a fixed outer piece on the opposite side of the changer, and means for shifting each of said movable pieces from contact with one of said inner pieces to contact with one of said outer pieces.

8. In adynamo electric machine, an armature, a plurality of coils mounted on said armature, and a circuit changer having a plurality of inner fixed contact pieces, a plurality of outer fixed contact pieces, and a plurality of movable contact pieces, the homologous terminals of each coil connected respectively to an inner piece and a movable contact piece, and each of the inner pieces being connected with a fixed outer piece on the oppositeside of the changer, and means for alternately bringing each of said movable pieces in contact with one of said inner pieces and with one of said outer pieces whereby the coil terminals are connected alternately with coil terminals on the same and on the opposite side of the circuit changer.

9. In a dynamo electric machine, an armature and a circuit changer, all of the terminals of the coils of said armature being connected to said circuit changer, and means for varying the connections between said coils, said means comprising two fixed rings and a movable ring, contact pieces connected to each of said rings, and means for shift- 'ing the contact pieces of said movable ring from contact with the pieces of one of said fixed rings into contact with the pieces of the other fixed ring.

10. In a dynamo electric machine, an armature and a circuit-changer, all of the terminals of the coils of said armature being connected to said circuit-changer, and means for varying the connections between said coils, said means comprising a movable ring having an aperture into which the shaft of said armature is threaded.

11. In a dynamo-electric machine, an armature and a circuit-changer comprising a plurality of contact pieces, all of the terminals of the coils of said armature being connected to said pieces, and means for varying the connections between said coils, said means comprising two fixed rings and a movable ring, some of said contact pieces connected to each of said rings, and means for shifting the contact pieces of said movable ring from contact with the pieces of one of said fixed rings into contact with the pieces of the other fixed ring, said shifting means comprising a movable ring having an aperture into which the shaft of said armature is threaded.

12. The combination of an armature of a dynamo-electric machine and means for changing the windings of said armature from wave to lap winding.

13. The combination of an armature of a dynamo-electric machine and means for changing the Winnings of said armature from a duplex lap winding to a simplex wave winding.

In testimony whereof I aifix my signature in the presence of two witnesses.

ERNEST J. ANDREWS. lVitnesses C. PAUL PARKER, LINCOLN B. ILIFF.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

